A typical pair of eyeglasses includes a pair of lenses or a single shield mounted to a frame that may include rims around the lenses; a brow bar; a bridge piece connecting the inner ends of the rims; and two temple pieces attached to the outer ends of the rims for resting the glasses on the user. Lenses are typically mounted to the eyeglass frame by a screw or other fastening device that tightens the rim around the lens. In the conventional configuration, the screw must be removed before the lens may be removed. The screw is often small and identifying the size and type of screw can require the user to strain his or her eyes. Removing the screw requires that the user have a screw driver or other tool that fits the particular screw in that pair of eyewear. Users will often not have the proper screwdriver. If the screw is broken or stripped, the user must then find a suitable replacement screw. This is inconvenient for the user as different eyeglasses use different kinds of screws which may have different head types and sizes. These different screws will often not work in different pairs of eyeglasses or with different screwdrivers. Additionally, if the screw breaks while in the glasses, the user may have difficulty removing the broken screw. Users may also desire to change lenses while wearing the glasses to accommodate different lighting conditions. Mounting lenses to the frame using screws can make this process highly inconvenient for the user.
Recently, prescription lenses have been developed with notches to make them interchangeable in brow bar designs if desired. This requires a forcing of the brow bar to go over the notches in the lenses. This technique can be quite cumbersome to work with in both the insertion and removal of the lenses.
Examples of various prior eyewear are disclosed in the following patents and publications, the disclosures of which are hereby incorporated herein by reference: U.S. Pat. Nos. 3,565,517 to Gitlin et al, 3,838,914 to Fernandez, 5,321,442 to Albanese, 6,592,220 to Cheong, and 6,866,386 to Chen; Japanese patent applications 59072417, 60140316, and 2004021086; and PCT patent application WO 96/37800.
Accordingly, there is a need for providing an easily replaceable, convenient mechanism for coupling interchangeable eyeglass lenses to frames.